Yes, the default on YOUR year model is heat when the valve fails. Newer 12 button Dometic the default is COOL. You CANNOT use a voltmeter to check current going to the reversing solenoid. You use a 40 watt light bulb holder with 6 inch pigtails to test for 120 volts. You either have a reversing coil bad or the Reversing valve bad. There is no way to test for a reversing valve other than replacing the coil and then if that does not fix it the valve is bad and Dometic does not supply that part. YES, you need the Bulb tester I mentioned above. Doug
